Motor driven camera

ABSTRACT

A co-ordination control system for a camera and a motor drive unit with separate electrical power sources one of which has a higher voltage than the other. The system is provided with an interface circuit including two switching elements arranged to cooperate with a common release button and connected between the circuitries of the camera and the unit so that the higher voltage of the source in the unit is prevented from being applied to the circuitry of the camera. For remotely controlled photographic purposes, the system is further provided with a control circuit for actuating these two switching elements in time-displaced relation to each other.

This is a continuation of application, Ser. No. 888,469, filed Mar. 20,1978 now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to motor driven cameras, and more particularly toa control system for co-ordinating a camera and a motor drive unit witha common release actuating button which may be provided in either one ofthem.

2. Description of the Prior Art

The conventional motor driven camera has two release actuating membersone in the camera body and the other in the motor drive unit, while thecamera is co-ordinated with the motor drive unit by making use of twoswitch elements S1 and S2 in the camera body 1, or S1D and S2D in theunit body 2 as shown in FIG. 1. When either one of the actuating membersor shutter release buttons is depressed, the first switch element S1 orS1D is closed to start light-metering operation by a circuit 5 in thecamera body 1, and is followed by closure of the second switch elementS2 or S2D which results in actuation of a camera release. At thecompletion of an exposure, a motor control circuit 6 is actuated todrive a film winding and shutter cocking mechanism for one cycle ofoperation. After each cycle of winding operation, the shutter releasebutton is rendered effective to perform the next actuation of the camerarelease.

Recently, a motor driven camera having a plurality of switched positionsfor a continuous succession of frame exposures at a high or slow speedand a single frame operation has been developed. In the case of thecontinuous succession of frame exposures, it is required to startoperation of the motor drive unit at the time of actuation of the camerarelease. For this purpose, the second switch element S2 or S2D isutilized to control actuation of operation of the motor. As theoperating voltage for the motor is generally set to 18 volts, beinghigher than that for the electromagnet controlling the period ofactuation of the shutter, for example, 6 volts, it has been the priorart practice to employ a reverse current preventing means or diode 7 asconnected between any one of the second switch elements S2 and S2D andthe camera control circuit 5, or otherwise the circuit 5 will be damagedby application of the excess voltage thereto, when the second switchelement S2 or S2D is opened to cut off the motor drive control circuit 6from the earth.

The employment of the reverse current prevent diode 7, however, givesrise to disadvantages that, because of a voltage drop (about 0.6 volts)across the diode 7, the satisfactory operating level for the camera mustbe increased by a corresponding voltage difference to shorten thelife-time of a battery in the camera body and to make it more difficultto effect satisfactory performance of the camera as the ambienttemperature is decreased, and that, because of the requirement of a highvoltage resisting characteristic for the diode 7, it is impossible tofablicate the diode 7 as a part of an integrated circuit with limitationto the design flexibility allowing a camera of reduced size and withincrease in the production cost.

It is an object of the present invention to provide a motor drivencamera of the type having a plurality of operating modes which hasovercome the above mentioned conventional drawbacks.

To achieve this, there is provided an interface circuit between thecircuitry of the camera body and that of the motor drive unit to preventapplication of an excessive voltage from the motor drive unit to thecamera when the second switch element is operated.

Another object of the present invention is to provide a motor drivencamera with an electronic device for remote control photography adaptedto cooperate with the above described interface circuit.

These and other objects and features of the present invention willbecome apparent from the following detailed description taken inconjunction with the accompanying drawings in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of a camera co-ordinated with amotor drive unit according to the prior art.

FIG. 2 is a perspective back view of one embodiment of a motor drivencamera according to the present invention.

FIG. 3 is an electrical circuit diagram, partly in block form, of thecamera of FIG. 2.

FIG. 4 is a perspective back view of another embodiment of the presentinvention.

FIG. 5 is an electrical circuit diagram, partly in block form, of thecamera of FIG. 4.

FIG. 6 is an electrical circuit diagram of an example of the oscillatorof FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 2 and 3 first to FIG. 2, there is shown a camera body11 with a motor drive unit 12 dismountably attached to the camera body11 along with a grip 13. Three release actuating buttons 14, 15 and 16are provided on the camera body 11, grip 13 and unit 12 respectively.The first button 14 is what is called the shutter button. The secondbutton 15 is located on the head of the grip 13 so that the operator iseasy to manipulate that button while holding the camera at the grip 13.The third button 16 may be advantageously used when the camera isdisposed with the right side upward. At the right hand back corner ofthe unit 12 are shown a plug 17 for remote control photography, a modeselector knob 18 having a plurality of switched positions including onesdesignated S (single frame operation), L (continuous succession of frameexposures with slow intervals) and H (continuous succession of frameexposures with fast intervals), a window behind which is positioned anindicator 20 for indicating occurrence of faulty operation of the motordrive unit resulting from, for example, no more fresh film frame, and acontrol button 23 for independent selection of the particular operatingmode H. A battery chamber in the unit 12 is indicated at 21. The camerabody 11 has a film winding lever 22 operable independently of the motordrive unit 12 to advance the film and to cock the shutter.

FIG. 3 shows the various circuit sections 30, 31 and 32 incorporated inthe camera body 11, grip 13 and unit 12 respectively, with fourinterconnection terminals 33a to 33d arranged on the camera housing tobe connectable with respective terminals 34a to 34d which are arrangedon the grip housing, and with additional six terminals 35a to 35f of thegrip housing arranged to be connectable with terminals 36a to 36f whichare arranged on the unit housing.

Block 30 includes an electrical power source or battery 37 whose voltageis set to a level, for example, 6 volts, a first switch element Sw1arranged upon depression of the shutter button 14 to a first stroke tobe moved from its "NC" to its "NO" position where a current flows fromthe battery 37 through series-connected resistors 40 and 41 to turn on afirst power supply control transistor 38 so that a light-meteringcircuit 39a starts to operate, and a second switch element SW2 arrangedupon further depression of the shutter button 14 to the second stroke tobe closed so that a second power supply control transistor 39b is turnedon to start operation of first and second electromagnets 39c and 39dcontrolling actuation of the camera release and an exposure determiningmeans respectively. The switch SW2 is connected between the terminal 33dand the minus side of the battery 37 and is closed by the operation ofthe release button 14. The switch SW5 is connected to the "NO" positionof the fixed contact connected to the terminal 33b when the exposure iscompleted, and the movable contact is designed to be connected to theminus side of the battery 37 together with the terminal 33a.

Between the plus side of the battery 37 and the NC position of the fixedcontact of the switch SW5, there are connected a magnetic releasecircuit 39c and an exposure determining circuit 39d. The base of thetransistor 39b is connected between the switch SW2 and the terminal 33dthrough a resistor, and when the switch SW2 is closed the transistor 39dbecomes on to supply power to the magnetic release circuit 39c as wellas the exposure determining circuit 39d. When the shutter is closed, aswitch SW5 is set from its "NC" to its "NO" position, where the firstand second electromagnets 39c and 39d are cut off from the battery 37 sothat the second switch element SW2 is no longer effective to actuate theelectromagnets 39c and 39d. Without the motor drive unit 12 and the grip13, when the lever 22 is cocked, the shutter is reset and the switch SW5is moved to "NO" position.

Block 31 includes an electric motor M, a diode 43 connected across thewinding of the motor M, a condenser 44 connected in parallel to thediode 43, these parts being connected at their one poles through acommon lead to the terminal 34a and at their opposite poles through acommon lead to the terminal 35b, a clutch C of the electromagnetic typethrough which motion of the motor M is transmitted to a film winding andshutter cocking mechanism not shown in the camera body 11 when thesolenoid 45 is energized, a diode 46 connected across the solenoid 45,and a condenser 47 connected in parallel to the diode 46, these partsbeing connected at their one poles through a common lead to the terminal34a and at their opposite poles through a common lead to the terminal35a. Block 31 further includes first and second switch elements SW1M andSW2M arranged to be closed when the button 15 is depressed through afirst stroke and then through a second stroke, respectively, with themovable contacts of SW1M and SW2M being connected through a common leadto the terminal 34a, and with the fixed contacts being connected throughrespective leads to the both of the terminals 34c and 35e and to theboth of the terminals 34d and 35f.

Block 32 comprises an electrical power source or battery 50 whosevoltage is set to a higher level than that of the battery 37 in thecamera body 11, for example, 18 volts, a main switch SW3 connected inthe negative bus, a motor drive circuit 53 responsive either to closureof the second switch element SW2V when in H mode or to "NO" setting ofthe shutter closure responsive switch SW5 when in L mode, or to "NO"setting of SW5 followed by the opening of the once actuated SW2V when inS mode, for energizing the motor M with electrical power supply from thebattery 50, a clutch drive control circuit 51 responsive either to "NO"setting of SW5 when in H or L mode or to "NO" setting of SW5 followed bythe opening of the once actuated SW2V when in S mode for energizing thesolenoid 45 with electrical power supply from the battery 50, a brakingcircuit 52 for the motor M, a mode selecting circuit 54, a monitoringcircuit 55 responsive to an excess of duration of winding operation forstopping the motor M and clutch C simultaneously from furtherenergization and for displaying the occurrence of such state, aninterface circuit 56, and an actuating circuit 57 having a similarfunction to that of the switch element assembly SW1V and SW2V, the SW1Vand SW2V being arranged to be closed when the third button 16 isdepressed to a first and second stroke respectively, and adapted for usein remote control photography, each of which will be explained in detailbelow.

The motor drive control circuit 53 comprises resistors R7 and R8connected in series to each other between the positive bus and a fixedcontact S of a mode selector switch SW6, a first transistor T4 with abase connected through a resistor R9 to a point on connection betweenresistors R7 and R8, and with an emitter connected to the positive bus,a second transistor T5 with a base connected to the collector of firsttransistor T4 and also to a point on connection between resistors R10and R11, and an emitter connected to the positive bus, and a thirdtransistor T6 with a base connected to the collector of secondtransistor T5, with a collector connected to the positive bus, and withan emitter connected through terminals 36b and 35b to the motor M. Theopposite end of resistor R11 is connected either to the negative busthrough a diode D5 and SW5 and to a fixed contact H of SW6, so thatconduction of the transistor T6 for the motor M is controlled, dependingupon the switched positions of SW5 and SW6.

The clutch drive control circuit 51 comprises a first transistor T9 witha base connected through a resistor R13 and the resistor R7 to SW6 at S,with an emitter connected to the positive bus and with a collectorconnected through a resistor R14 and SW5 to the negative bus, and asecond transistor T10 with a base connected to the collector of thefirst transistor T9 and with an emitter and collector connected in thepower supply line to the clutch solenoid 45.

The motor braking circuit 52 comprises a first transistor T7 with a baseconnected to a point on connection between the collector of transistorT5 and a resistor R12 and with an emitter connected to the emitter ofthe transistor T6 so that when the transistor T6 for the motor M isrendered nonconducting, a second transistor T8 connected across thewinding of the motor M is rendered conducting by the first transistor T7having a collector connected to the base of the second transistor T8.

The monitoring circuit 55 includes a resistor R6, and a timing capacitorC1 connected in series to the resistor R6 between the collector of thetransistor T10, and the fixed contact "NO" of SW5 through terminals 36d,35d, 34b and 33b, so that when a particular winding operation is notcompleted within a time interval, for example, 500 milliseconds,determined to be longer than that necessary to complete one cycle ofnormal winding operation and usually ranging from 100 to 300milliseconds, the timing circuit produces an output which is applied toa base of a transistor T2 with an emitter connected to a point onconnection between resistors R4 and R5 and with a collector connectedthrough a diode D1 both to the base of transistor T4 through theresistor R9 and to the base of transistor T9 through the resistor R13,thereby the transistor T4 is turned on to de-energize the motor M, andthe transistor T9 is turned on to de-energize the clutch C. Conductionof the transistor Tr2 also causes conduction of a transistor T1 so thata light-emitting diode 20 as the indicator of FIG. 2 is energized to belit, informing of a fact that no more fresh area is available in thefilm, for example. The transistor T1 has an emitter connected to thepositive bus, a collector connected through a resistor R1 to thelight-emitting diode 20, and a base connected to a point on connectionbetween resistors R2 and R3 which are connected between the positive busand the collector of the transistor T2. To discharge the timingcapacitor C1 when each cycle of normal winding operation is completed,there is provided a transistor T3 with a collector connected to thepositive pole of the capacitor C1, with an emitter connected to thenegative pole of the capacitor C1, and with a base connected through theresistors R5 and R4 to the positive bus so that when SW5 is set to "NC"position, the transistor T3 is turned on to short-circuit the timingcapacitor C1, as a diode D3 is connected between the resistor R6 andcapacitor C1 and a diode D4 is connected between the capacitor C1 andthe base of transistor T3.

The interface circuit 56 includes a capacitor C3 which is charged toabout 6 volts from the battery 37 in the camera body through a resistorR27, terminals 36e, 35e, 34c and 33c, SW1 in "NC" position, and theresistors 40 and 41 before the button 16 is depressed, and a firstswitching element or transistor T17 with a base connected to thepositive pole of the capacitor C3 and with an emitter connected to thefixed contact of SW1V, so that when SW1V is closed, a current is drawnfrom the base of the transistor T17 by the charge on the capacitor C3.The collector of the transistor T17 is connected to the positive busthrough resistors R28 and R29 which are connected in series to eachother. A point on connection between the resistors R28 and R29 isconnected to a base of a transistor T16 with an emitter connected to thepositive bus and with a collector connected through a resistor R23, adiode D7 and a resistor R26 to the base of the transistor T17, so thatonce the transistor T17 is turned on, the conduction of the transistorT17 is held so long as the SW1V is closed. The interface circuit 56further includes a second switching element or transistor T15 with anemitter connected to the fixed contact of SW2V, with a base connected toa point on connection between a resistor R24 and a diode string D8 whichare connected between the resistor R23 and the negative bus, and with acollector connected to a movable contact of the switch SW4 so that whenthe SW2V is closed, the transistor T15 is effective to actuate the motordrive control circuit 53 for energization of the motor M, provided thatthe SW6 is in H position, or the SW4 is in "NO" position for the H mode.When the once closed switch SW2V is opened, the transistor T15 isrendered non-conducting to actuate the motor and clutch drive controlcircuits 53 and 51 for energization of the motor M and the clutch Csimultaneously, provided that SW6 is in S position and SW4 is in "NC"position.

The actuating circuit 57 includes a first transistor T14 having asimilar function to that of SW1, SW1M or SW1V with a collector connectedto the fixed contact of SW1V, and with an emitter connected to thenegative bus, a second transistor T13 having a similar function to thatof SW2, SW2M or SW2V with a collector connected to the fixed contact ofSW2V and with an emitter connected to the negative bus, and a circuitresponsive to appearance of an actuating signal at the plug 17 forcausing the first and second transistors T14 and T13 to be conducting intime-displaced relation as determined by a timing circuit of a resistorR18 and a capacitor C2. This circuit comprises a resistor R15 connectedbetween one terminal of the plug 17 and the positive bus, a seriescircuit of a constant voltage diode D6, and two resistors R16 and R17, atransistor T11 with a base connected to a point on connection betweenthe resistor R16, and R17, with an emitter connected to the positivebus, and with a collector connected through a resistor R22 to the baseof the transistor T14, and a transistor T12 with a base connected to theoutput of the timing circuit, with an emitter connected to a point onconnection between resistors R20 and R21 which are connected between thecollector of the transistor T11 and the negative bus, and with acollector connected to the base of the transistor T13 and also to thenegative bus through a resistor R19.

The operation of the motor driven camera of FIGS. 2 and 3 is as follows.When a continuous succession of frame exposures with fast intervals areto be made, the operator will turn the control knob 18 to place a symbolH in registry with an index not shown. Instead of using the control knob18, the button 23 may be depressed provided that the control knob 18 wasset to either one of the positions L and S. When either one of therelease actuating buttons 15 and 16 is depressed to a first stroke, theswitching transistor 38 in the camera body is turned on so that thelight-metering circuit 39a starts to operate in a manner similar to thatin which the camera operates without the motor drive unit. Upon furtherdepression of the button 15 or 16, the first electromagnet 39c isactuated to initiate an exposure, and at the same time, the motor M isdriven for rotation as a current flows through a circuit which can betraced from the positive bus through the resistors R10 and R11, SW6,SW4, transistor T15 and SW2V to the negative bus, while the clutch Cremains de-energized so that motion of the motor M is not transmitted tothe film winding mechanism. When the shutter is closed to terminate theexposure, SW5 is set from "NC" to "NO" position where the clutch C isactuated to start transmission of motion of the motor M to the filmwinding mechanism. When the shutter is reset to the cocked position, SW5is set again to "NC" position where the transistor T10 is turned off todeactuate the clutch C, and a next release of the camera is actuated fora second frame exposure since the release button 15 or 16 remainsdepressed. Such procedure repeats itself until the force exerted todepress the button 15 or 16 is removed. If this occurs at a point intime during the winding process, the conduction of the transistor T5 isretained by the diode D5. When the winding operation is completed to setSW5 to "NC" position, the transistor T5 is turned off and then thetransistor T6 is turned off. Non-conduction of the transistor T6 causesgeneration of a potential difference between the emitter and base of thetransistor T7 which causes conduction of the transistor T8, thereby thewinding of the motor M is short-circuited to brake the motor M. It is tobe understood that the voltage of the battery 50 in the motor drive unit12 is prevent from applying to the control circuit 30 in the camera body11 by making use of the first and second electronic switching elementsT17 and T15 respectively as arranged to cooperate with the first andsecond mechanical actuating switches SW1V and SW2V.

In L mode, the full depression of the button 15 or 16 leads to themaking of a first exposure in a manner similar to that described inconnection with H mode, but not to the simultaneous occurrence of theenergization of the motor M, because the motor drive control circuit 53is cut off from the interface circuit 56 at the mode selector switchSW6. When the sutter is closed to set the SW5 to "NO" position, a basecurrent of the transistor T5 is allowed to flow through the resistorR11, diode D5, terminals 36d and 35d and the switch SW5 in "NO" positionto the negative bus. At the same time, a base current of the transistorT10 is allowed to flow through the resistor R14, terminals 36d and 35d,and the switch SW5 in "NO" position to the negative bus. Therefore, themotor M and the clutch C are simultaneously actuated to advance the filmthrough the length of one frame. When SW5 is set again to "NO" position,the motor M and the clutch C are de-energized, and the braking circuit52 starts to operate in a manner similar to that when in H mode. If thebutton 15 or 16 remains depressed at this time, the setting of SW5 to"NC" position starts to actuate a second release of the camera. It is tobe noted here that when in L mode, a time interval between thetermination of the first exposure and the initiation of the secondexposure is longer than that in H mode by a magnitude corresponding tothe speeding-up transient of the motor M.

For single frame operation, it is convenient that SW6 is left set in Sposition because H mode is available by operating SW4 regardless of the"S" setting of SW6, and because L mode is available by operating theshutter button 14 regardless of what position the SW4 and SW6 are setin. Unlike the modes H and L, it is made impossible in L mode to startthe energization of the motor M and clutch C at the time of setting SW5from "NC" to "NO" position, so long as the button 15 or 16 remainsdepressed, since the transistors T4 and T9 are turned on by the outputof the transistor T15 to maintain the transistors T6 and T10non-conducting with the result that the motor M and clutch C remainsstationary at that time. When the force exerted to depress the button 15or 16 is removed, the transistor T15 is turned off to effect the startof energization of the motor M and clutch C simultaneously. The settingof SW5 to "NC" position leads to actuation of the next stage transistorsT5 and T10 for non-conduction, resulting in the de-energization of themotor M and clutch C.

In photography with a remote control device having an operating memberconnected to the plug 17, when the circuit 57 is short-circuited at theplug 17, a base current of the transistor T11 is allowed to flow throughthe resistor R17, and constant voltage diode D6. Conducting of thetransistor T11 causes conducting of the transistor T14 which producesthe same function as that of SW1V when closed. As the time constant ofthe timing circuit R18 and C2 is adjusted by taking into account thelight-response characteristics of the exposure control circuit, theconduction of the transistor T14 is followed after that time constant bythe conduction of the transistor T13 which produces the same effect asthat of the closure of SW2V.

Referring to FIGS. 4, 5 and 6, there is shown another embodiment of themotor driven camera according to the present invention. As shown in FIG.4, there is provided an interval control knob 105 for controlling thetime intervals between the successive two frame exposures in discretemanner positioned on the unit housing 102. The third release button 16of FIG. 2 is not employed. In FIG. 5, the circuitry of the motor drivencamera is shown as comprising two sections enclosed in dot-and-dashedline blocks 111 and 112 incorporated in the camera body 101 and themotor drive unit 102, the latter being dismountably attached to theformer and being electrically connected thereto through interconnectionterminals 113a to 113d on the camera housing and through interconnectionterminals 114a to 114d on the unit housing.

Block 111 includes a battery of a low voltage (for example 6 volts), apower supply control transistor 116, an exposure control circuit 117 ofsimilar construction to that of the circuit 30 of FIG. 3, that is,including similar parts 117a to 117d to those 39a to 39d respectively,and first and second actuating switches SW11 and SW12 arranged tocooperate with the shutter release button 103 in a similar manner tothat described in connection with FIGS. 2 and 3. When the shutter button103 is depressed to the first stroke, the first switch SW11 is set from"NC" to "NO" position where a series circuit of resistors 118 and 119 isconnected to the battery 115, thereby the transistor 116 is renderedconducting to initiate operation of the light-metering circuit 117a.Upon further depression of the button 103 to the second stroke, thesecond switch SW12 is closed to energize the first electromagnet 117ccontrolling actuation of the shutter release, and also to energize thesecond electromagnet 117d controlling the period of actuation of theshutter. When the shutter starts to be closed, a switch SW15 is movedfrom "NO" to "NC" position where an actuating signal of binary "0" levelfor the circuit 112 appears at the terminal 113c.

Block 112 includes a battery 120 of high level (for example, 18 volts)to which a clutch drive circuit 121, motor drive and brake circuit 122,power supply control circuit 123 for a pulsated co-ordination controlsystem, mode selecting circuit 124, interface circuit 125, releaseactuating circuit 126 and control circuit 127 for the circuit 126 areconnected in parallel through a main switch SW16. The co-ordinationcontrol system comprises a pulse forming circuit 128, gating network 129and reset pulse forming circuit 130. These circuits will next beexplained in detail in connection with the various operating modes.

The clutch drive circuit 121 comprises a solenoid of electromagnet typeclutch C1, and a tansistor Tr11 with a base connected through a resistorR64 to the positive bus and through a resistor R65 to a transistor Tr2in the gating network 129 and with a collector and emitter connectedrespectively to one end of the solenoid C1, the opposite end of thesolenoid C1 being connected to the circuit earth, and to the positivebus.

The motor drive and brake circuit 122 comprises a winding of a motor M1,a switching transistor Tr9 with a collector connected to the positivebus, with an emitter connected to one end of the motor winding M1, theopposite end of which is connected to the circuit earth, a transistorTr8 with a connector connected to a base of transistor Tr9 and with abase connected through a resistor R62 to a collector of a transistor Tr1in the gating network 129 and through a resistor R63 to the positivebus, and a transistor with a collector and emitter connected across themotor winding M1 and with a base connected to the output stage of thetransistor Tr8 which includes a resistor R66 connected between thecollector of the transistor Tr8 and the circuit earth.

The power supply control circuit 123 comprises a transistor Tr7 with anemitter connected to the positive bus and with a collector connected toa terminal 131a which is connected to all of terminals 131b and 131c onthe circuits 129 and 128 respectively. The base of transistor Tr7 isconnected both to the terminal 114b through a resistor R67 and theinterface circuit 125 and to the terminal 114c through a resistor R68.

The mode selecting circuit 124 comprises a first switch SW13 having twoswitched positions, a, and, b, for allowance of selection of anyoperating mode and for the priority of H mode and connected at itsmovable contact through the interface circuit 125 to the terminal 114b,and a second switch SW14 having a movable contact connected to the fixedcontact, a, of the first switch SW13 and having four fixed contacts, S,OFF, L and H connected through respective resistors R59, R60 and R61,except for OFF contact, to the positive bus, the contact H being alsoconnected to the fixed contact, b, of the first switch SW13.

The interface circuit 125 comprises a transistor Tr6 with a baseconnected to a point on connection between a resistor R58 and a diodestring D52 which are connected between the positive and negative buses,with an emitter connected to the terminal 114b and with a collectorconnected to both of the circuits 123 and 124.

When the release button 104 of FIG. 4 is fully depressed to close thesecond actuating switch SW12M, a signal of "0" level appears at theterminal 113b and is directed through the terminal 114b and theconducted transistor Tr6 to the power supply control transistor Tr7 andto the mode selecting circuit 124.

With the switch SW13 set in "b" position, or with the combination ofSW13 set in "a" position and SW14 set in "H" position, the lattersetting being effected by operating the knob 107, the aforesaid signalof "0" level is directed to a NOR gate G9 and AND gate G10 at inputs, b,and, a, respectively, and further through an inverter I5 to an OR gateG16 at an input, a, while two signals of binary "1" level are appliedfrom the contacts S and L of SW14 the former signal both to an OR gateG2 at an input, b, through an inverter I1 and to an AND gate G11 at aninput, a, through a terminal 135a-and-terminal 135b connection thelatter signal to an OR gate G5 at an input, b.

During each frame exposure, the switch SW15 remains in "NO" position sothat a signal of "1" level appears at the terminal 113c. This signal isdirected through the terminal 114c both to an AND gate G3 at an input,a, through a terminal 132a-and-terminal 132b connection and an inverterI2 and to a NAND gate G6 at an input, a, through a terminal132a-and-terminal 132c connection and an inverter I3, thereby a clockpulse train from a first flip-flop F1 is prevented from passing throughthe AND gate G3 to a second flip-flop F2. In consequence, (n-1) numberof flip-flops F2 to Fn are all set with signals of "0" level appearingat the output stages Q thereof and being applied to the inputs T of therespective next flip-flops F3 to Fn.

The output signal of "0" level from flip-flop F6 is directed to an ANDgate G7 which produces a signal of "0" level. Responsive to this signaland the signal of "0" level from H contact of SW14, the NOR gate G9produces a signal of "1" level which is applied through an OR gate G12to the base of the first transistor Tr1, thereby the transistors Tr8 andTr9 are turned on to energize the motor winding M1. On the other hand,as the switch SW15 is in "NO" position, the aforesaid signal of "1"level is applied through the inverter I3 to the input, a, of the NANDgate G6. A signal of "1" level from the NAND gate G6 is applied to aninput, a, of a NOR gate G8 which produces a signal of "0" level.Responsive to this signal, the next stage AND gate G11 produces a signalof "0" level which is applied to an input, a, of an AND gate G13,thereby the transistors Tr2 and Tr11 are prevented from conducting, andthe clutch solenoid C1 is not energized. In H mode, therefore, the fulldepression of the button 103 leads to the start of energization of themotor M but not to the start of operation the clutch C.

At the termination of duration of each frame exposure, the output ofSW15 changes from "1" to "0" level, the latter appearing at the terminal132a. This signal after being inverted to "1" level by I3 is applied tothe input, a, of the NAND gate G6, while the input, b, of the NAND gateG6 is receptive of a "1" signal from the contact L of SW14 through theOR gate G5. Responsive to the output signal of "0" level from the NANDgate G6 and the aforesaid output signal of "0" level from the AND gateG7, the NOR gate G8 produces an output signal of "1" level which isapplied to the input, b, of the AND gate G11. Responsive to the outputsignal of "1" level from the contact S of SW14 through the terminal 135band the output signal of "1" level from the NOR gate G8, the AND gateG11 produces an output signal of "1" level which is applied to theinputs, a, of the OR gate G12 and the AND gate G13. As the signal of "0"level from the contact H of SW14 was applied through the inverter I5 andthe OR gate G16 to the input, b, of the AND gate G13, when the switchSW15 is set to "NC" position, the output of the AND gate G13 changesfrom "0" to "1" level, thereby the transistors Tr2 and Tr11 are turnedon to energize the clutch solenoid C1. From this onward, motion of themotor M is transmitted to the film winding mechanism in the camera body.

When the transistor Tr2 changes from the non-conducting to theconducting state with simultaneous occurrence of a change of the outputof an inverter I4 from "0" to "1" level, a ramping pulse is applied froma condenser C52 through a diode D57 to all the reset terminals of theflip-flops F1 to Fn. Now assuming that no more fresh area is availablein the film, then the winding operation can not be completed within atime interval, for example, 640 milliseconds. At the termination ofduration of this time interval, the output of the flip-flop F6 changesfrom "0" to "1" level, the latter being applied to the input, a, of theAND gate G7. Whilst a latch circuit L3 was set by the output of theinverter I4 at the start of conduction of the transistor Tr2 to producean output of "1" level which is applied to the input, b, of the AND gateG7, the transistors Tr1 and Tr2 are turned off to de-energize the motorM1 and clutch C1. The output signal of "1" level from the AND gate G7after being inverted by an inverter I6 to "0" level is applied to aninput, a, of an AND gate G1, thereby a pulse train is gated off not topass from an oscillator Fo to the flip-flop F1. The output of theinverter I6 is applied through an inverter I0 to a base of a transistorTr0 having an emitter connected to the circuit earth and having acollector connected through a light-emitting diode 108 to a voltagesource E. Since the diode 108 is lit, the operator is informed of a factthat the used film has come to an end. The latch circuit L3 is reset bya pulse from a condenser C54 and a resistor R53 when the switch SW15 isset from "NC" to "NO" position.

Alternately assuming that the winding operation is completed within thepredetermined time interval, in this instance, 640 milliseconds, whenSW15 is set to "NO" position, the signal appearing at the terminal 132achanges from "0" to "1" level. As mentioned above, when this signal isof "1" level, the output of the AND gate G11 is of "0" level, so thatthe clutch C1 is no longer effective to transmit motion of the motor M1to the film winding mechanism, while the motor M1 is maintainedenergized provided that SW12M remains closed.

In L mode, the motor M1 starts to rotate after a desired time intervalfrom the termination of the preceding exposure, and then the clutch C1starts to be effective for driving torque transmission after apredetermined time interval from the start of movement of the motor M1.In the latter connection, this time interval is determined to be equalto or slightly longer than that necessary to increase the speed ofrotation of the motor from zero to a normal level. For this purpose, thereset pulse forming circuit 130 further includes a condenser C53connected at one pole to the output of the AND gate G11 and at theopposite pole connected both to the circuit earth through a resistor R52and to the common output terminal of the aforesaid condenser C52 anddiode D57 through a diode D56. In a time interval of about 40milliseconds after the all flip-flops F1 to Fn are reset by the outputof the diode D56, the output Q of the flip-flop F2 changes from "0" to"1" level. This signal is applied to an input T of a latch circuit L4which produces an output of "1" level. The output Q of the latch circuitL4 is connected to an input, b, of the AND gate G10 having an outputconnected to an input, b, of the OR gate G16. The output of the OR gateG16 is connected to an input, b, of the AND gate G13, so that thetransistor Tr2 is turned on in response to the output Q of "1" levelfrom the flip-flop F2.

To set a desired time interval in the circuit 112, the operator willturn the knob 105 of FIG. 4 to place an indicium in registry with anindex. This knob 105 cooperates with a switch SW17 having a plurality ofswitched positions, CO1, CO2, . . . , CO20 for production of 160, 320milliseconds, . . . , 20 seconds, for example, respectively.

When the release button 104 is fully depressed to close the switchSW12M, a signal of "0" level appears at the fixed contact L of theswitch SW14 and is applied to the "b" input of the OR gate G5, while the"a" input of the OR gate G5 is receptive of a signal of "0" level from alatch circuit L2, since the switch SW15 is in "NO" position where allthe flip-flops F2 to Fn are stopped to count clock pulses from theflip-flop F1 by the output of the inverter I2. Responsive to the outputof "0" level from the AND gate G7, the next stage gate G6 produces anoutput of "1" level which is applied to the NOR gate G8. Responsive tothe output of "0" level from the NOR gate G8, the AND gate G11 producesan output of "0" level, so that the transistors Tr1 and Tr2 remain inthe non-conducting states.

At the termination of the first exposure, the switch SW15 is set to "NC"position. Although the signal at the terminal 132a changes to "0" level,the output of the OR gate G5 remains of "0" level until the latchcircuit L2 is set to change the output from "0" to "1" level. With theswitch SW17 set in "CO20" position as shown in FIG. 5, after 20 secondsfrom the time at which the switch SW15 is set to "NC" position, thelatch circuit L2 is set by the output Q of the flip-flop Fn with theresult that the motor M1 starts to rotate. Although the output of theAND gate G11 changes to "1" level, the OR gate G16 continues to producean output of "0" level until the latch L4 is set by the output of theflip-flop F2. When the latch L4 is set, the outputs of the AND gate G10,OR gate G16 and AND gate G13 change from "0" to "1" level so that theclutch C1 is effective to operate the film winding mechanism. When SW15is set to "NO" position, the motor M1 and clutch C1 are de-energizedsimultaneously. Such procedure repeats itself until a desired number offrame exposures are taken in sequence.

For single frame operation, the operator will turn the knob 107 to placethe symbol S in registry with a not shown index. When the button 104 isfully depressed to close SW12M, a signal of "0" level appears at thefixed contact S of SW14, while two signals of "1" level appear at thefixed contacts L and H. The signal of "0" level is applied throughterminal 135a-and-terminal 135b connection to the input, a, of the ANDgate G11 so that the motor M1 and clutch C1 remain de-energized. Whenthe exposure has been completed to set SW15 to "NC" position, and thenis followed by the opening of SW12M, simultaneous appearance of "1"signals at the "a" and "b" inputs of the AND gate G11 occurs to startrotation of the motor M1. On the other hand, the output of the inverterI1 changes to "0" level with the start of operation of the oscillatorFo. In the predetermined time interval from the start of rotation of themotor M1, the flip-flop F2 is set, causing the output of the latch L4 tochange to "1" level, with the result that the clutch C1 is effective totransmit motion of the momotor M1 to the film winding mechanism. WhenSW15 is set to "NO" position, the motor M1 and clutch C1 arede-energized, and the power supply control circuit Tr7 is renderednon-conducting.

In photography with a remote control device having an operating memberconnected to the plug 106, when the two terminals, a, and, b, of theplug 106 are short-circuited, a transistor Tr4 is rendered conducting toshort-circuit the first actuating switch SW11M. The base of thetransistor Tr4 is connected through a resistor R57 to the collector of atransistor Tr3 with an emitter connected to the positive bus, and with abase connected to a point on connection between resistors R55 and R56which are connected between the positive bus and a constant voltagediode D51. Connected in parallel to the series circuit of transistorsR55 and R56 and the diode D51 is a resistor R54. Conduction of thetransistor Tr3 also causes power supply to the pulse forming circuit 128through a terminal 136a-and-terminal 136b connection and through a diodeD60. In a predetermined time interval from the start of conduction ofthe transistor Tr4, the flip-flop F1 is set to produce an output whichis applied to an input T of a latch L1, with an output Q connected to aninput, b, of an AND gate G14. Another input, a, of the AND gate G14 isconnected to the collector of the transistor Tr3, so that when both ofthe inputs of the AND gate G14 are of "1" level, a second switchingtransistor Tr5 is rendered conducting to short-circuit the secondactuating switch SW12M. When the transistor Tr3 is turned off, the latchL1 is reset by the output of an inverter I10.

FIG. 6 shows the details of the oscillator Fo of FIG. 5 as comprising afirst NOR gate A, a second NOR gate B having an input connected to anoutput of the NOR gate A, a resistor RT, a condenser C51 connected inseries to the resistor RT, the series circuit of the resistor RT andcondenser C51 being connected between the outputs of the first andsecond NOR gates A and B to constitute an unstable multivibrator, and atransistor TRe with a collector connected to a point on connectionbetween the output of the series circuit and the input of the first NORgate A with an emitter connected to the circuit earth and with a baseconnected to a terminal Re. When a reset pulse of "1" level is appliedto the terminal Re, the transistor TRe is rendered conducting todischarge the condenser C51 so that the output Q of the oscillator Fo ismaintained at "0" level.

What is claimed is:
 1. A camera system comprising:(A) a cameraincluding:(a) first power source means for supplying a voltage, (b) anexposure control circuit connected to the first power source means, (c)first switch means connected to the exposure control circuit forswitching between a first position for actuating the exposure controlcircuit and a second position for disabling the exposure controlcircuit, a connecting point between the first switch means and theexposure control circuit for forming a potential, (B) an electric drivedevice including:(d) second power source means having a voltage higherthan that of the first power source means, (e) an electric drive controlcircuit connected to the second power source means, (f) voltagegenerating means connected to the second power source means, (g)resistive means connected between the second power source means and thevoltage generating means,said resistive means forming a contact pointfor setting at the contact point a potential between the voltagegenerating means lower than that at the first power source means, (h) atransistor having a base connected between the voltage generating meansand the resistive means and having an emitter for producing an emittercurrent corresponding to the base voltage,said transistor having anemitter connected to the connecting point between the first switch meansand the first control circuit, said transistor having a collectorconnected to the driving control circuit, said transistor being set toconduct when the first switch means in in the first position and set tobe inverted when the first switch means is in the second position.
 2. Acamera system according to claim 1, wherein the electric drive device isremovably attached to the camera, and the electric drive device and thecamera have respective connection terminals for transmitting the outputof the transistor.
 3. A camera system according to claim 2, wherein thedrive device further comprises second switch means connected parallel tothe first switch means.
 4. A camera system according to claim 3, whereinthe electric drive device further comprises:a switching elementconnected parallel to said second switch means, signal generating meansfor controlling the switching element.
 5. A camera system according toclaim 4, wherein the signal generating means has an input terminal forreceiving an external signal and for generating a signal to actuate theswitching element when the external signal is applied to the terminal.6. A camera with an electric drive device comprising:first power sourcemeans for producing a voltage; an exposure control circuit connected tothe first power source means; first switch means for switching between aclosed position and an open position, said first switch means supplyingpower from the first power source means to the exposure control circuitwhen said first switch means is closed and inhibiting power when saidfirst switch means is opened; second switch means for switching theexposure control circuit off when it is opened and switching theexposure control circuit on when it is closed; second power source meansfor supplying a higher voltage than the first power source means; anelectric driving control circuit connected to the second power sourcemeans; accumulating means for charging from the first power source meanswhen the first switch means is opened and for discharging when the firstswitch means is closed; a first transistor for being turned on by thedischarge of the accumulating means; a second transistor for beingturned on by the turning-on of the first transistor, said secondtransistor forming a self-holding circuit together with the firsttransistor, and a third transistor having a base for receiving theoutput of the second transistor, having an emitter connected to thesecond switch means, having a collector connected to the electricdriving control circuit, for turning on when the second switch means isclosed and for turning off when the second switch means is opened, so asto control the operation of the electric drive control circuit.
 7. Acamera according to claim 6, further comprising third switch meansconnected parallel to the first switch means, and fourth switch meansconnected parallel to the second switch means.
 8. A camera according toclaim 7, further comprising a first switching element connected parallelto the third switch means, a second switching element connected parallelto the fourth switch means, and signal generating means for controllingthe first and second switching elements.
 9. A camera according to claim8, in which the signal generating means comprises an input terminal andis arranged to generate a signal for actuating the first and secondswitching elements when an outside signal is applied to the inputterminal.